Composition comprising naphthenic distillate, hydro-cracked lube and an antioxidant

ABSTRACT

A lubricant composition comprises an unhydrorefined naphthenic distillate and a hydrocracked lube oil (preferably solvent extracted or hydrorefined to reduce or inhibit sludging on exposure to light) having a viscosity in the range of 80-3,000 SUS at 100*F and an oxidation inhibitor in amount effective to permit said composition to pass the ASTM D-943 oxidation test for a period of at least 300 hours, said amount being less than would be required to permit the same D-943 test performance for a similar composition wherein the hydrocracked lube oil is replaced by an unhydrocracked solvent refined lube of the same viscosity, viscosity-gravity constant, and viscosity index. The composition is useful in formulation of engine oils, refrigeration oils, transmission fluids, turbine oils, hydraulic oils, textile machinery lubricants, mist lubricants, etc.

United States Patent [191 Bryer et al.

[ COMPOSITION COMPRISING NAPHTHENIC DISTILLATE, HYDRO-CRACKED LUBE AND AN ANTIOXIDANT [75] Inventors: Robert P. Bryer, Claymont, Del.;

Thomas D. Newingham, Broomall, Pa.; Ivor W. Mills, Media, Pa.; Glenn R. Dimeler, West Chester, Pa.

[73] Assignee: Sun Oil Company of Pennsylvania, Philadelphia, Pa.

22 Filed: Oct. 16, 1972 211 App]. No.: 298,126

3,403,092 9/1968 Rausch 208/18 X 3,419,497 12/1968 Rocchim et a 208/19 X 3,493,505 2/1970 Ries et a1. 208/18 X 3,598,740 8/1971 Duling et al. 252/73 Oct. 28, 1975 5/1972 Cummins 208/18 OTHER PUBLICATIONS Jones Oil & Gas Jour. 11/1/54, pp. 81-84.

57 ABSTRACT A lubricant composition comprises an unhydrorefined naphthenic distillate and a hydrocracked lube oil (preferably solvent extracted or hydrorefined to reduce or inhibit sludging on exposure to light) having a viscosity in the range of 80-3,000 SUS at 100F and an oxidation inhibitor in amount effective to permit said composition to pass the ASTM D-943 oxidation test for a period of at least 300 hours, said amount being less than would be required to permit the same D-943 test performance for a similar composition wherein the hydrocracked lube oil is replaced by an unhydrocracked solvent refined lube of the same viscosity, viscosity-gravity constant, and viscosity index. The composition is useful in formulation of engine oils, refrigeration oils, transmission fluids, turbine oils, hydraulic oils, textile machinery lubricants, mist lubricants, etc.

5 Claims, 3 Drawing Figures OH 0 w 0 m 0 v BONVQHOSSV COMPOSITION COMPRISING NAPI-ITI-IENIC DISTILLATE, HYDRO-CRACKED LUBE AND AN ANTIOXIDANT BACKGROUND OF THE INVENTION US. Pat. Nos. 3,617,484 (Nov. 12, I971), 3,663,427 (Max 16, 1972) and 3,666,657 (May 30, 1972), for example, describe the production of high viscosity index,

hydrocracked lube oils and a process of improving the stability of such oils, when exposed to ultraviolet light (especially in the presence of oxygen), by selective extraction of the hydrocracked oil with an aromatic selective solvent (e.g., furfural, phenol, etc.).

It has been discovered that certain stabilized hydrocracked oils can be characterized as having a shorter life (to an acid number end point) in the ASTM D-943 test (with an oxidation inhibitor) than do similar unstabilized hydrocracked oils. However, compositions containing such a stabilized oil and an oxidation inhibitor have a better D-943 life (as to an increased acid number of 2.0) than does a similar composition containing a conventional solvent refined oil instead of the stabilized hydrocracked oil.

SUMMARY OF THE INVENTION Hydrocracked lub oils, especially those having as ASTM viscosity index greater than 85 (typically at least 100) and containing in the range of 3-30 wt. percent aromatics, are especially useful components of petroleum based lubricant compositions and/or functional fluids. Such hydrocracked lubes are especially useful in compositions which also contain an antioxidant, particularly the phenolic types, e.g., ditertiarybutyl paracretive to improve oxidation inhibitor response of the hydrocracked lube.

An especially useful lubricant composition comprises an unhydrorefined naphthenic distillate and a hydrocracked lube oil which has been solvent extracted or hydrorefined to reduce or inhibit sludging on exposure to light and having a viscosity in the range of 803,000 SUS at I00F., and an oxidation inhibitor in amount effective to permit said composition to pass the ASTM D-943 oxidation test (to a total acid number increase of 2.0) for a period of at least 300 hours (more preferred, 500 hours), said amount being less than would be required to permit the same D-943 test performance for a similar composition wherein the hydrocracked lube oil is replaced by an unhydrocracked solvent refined lube of the same viscosity, VGC and viscosity index. In such a composition, where the hydrocracked oil is stabilized by extraction or hydrorefining, said D-943 life will be less than if an unstabilized hydrocracked lube were used. However, the formation of sludge in the D-943 test (which, for example is important in turbine oils) is less for compositions containing the stabilized hydrocracked oil.

BRIEF DESCRIPTION OF THE DRAWINGS The novel composition, comprising a stabilized hydrocracked lube and an antioxidant, is especially useful in such lubricants as mist oils, textile machinery lubricants, engine oils and hydraulic oils, which contain a high molecular weight polymer of the viscosity index builder class, such as polyacrylates, polymethacrylates, dispersant polyacrylates and polymethylacrylates (typically grafted with N-vinyl-2-pyrrolidinone), polystyrenes (e.g., polymethyl styrenes), polyolefins (e.g., polybutenes), or mixtures of two or more of such polymers. The accompanying drawings FIGS. 1 and 2, are typical infra-red absorption spectra (or scana) of two such commercial polymers, which are especially useful in engine oils to improve the viscosity index thereof. FIG. 3 is an IR scan of a typical engine oil additive package" of the DI or dispersant-inhibitor type.

As articles of commerce, such polymers are well known and readily available but are generally trade secret compositions which require expensive analytical work to completely characterize andcan require expensive laboratory work to duplicate. An important laboratory tool for identifying a particular commercial polymer is the infra-red (IR) scan. The scans of all of the FIGS. l-3 are of commercially available additives and are provided in order to facilitate practice of the embodiment of the present invention wherein the commercial additives can be used.

FIG. 1 is an IR scan of a typical commercial dispersant type polymethacrylate viscosity index builder, or improver. marketed by Rohm and Haas as Acryloid 954. This VI builder and other typical builder polymers are described further in pending US. application Ser. No. 246,997 (tiled Apr. 24, 1972) now US. Pat. No. 3,855,135, issued Dec. 17, I974 [generally. the lower molecular weight materials are preferred in mist lubricants or in shear stable engine oils].

FIG. 2 is an IR scan of another commercial VI builder which is marketed by Lubrizol Corporation as 3702" and termed a dispersant type styrene copolymer (note, the IR scan shows a high carbonyl content).

FIG. 3 is an IR scan of Lubrizol 27563 and represents another class of commercial engine oil additive, the Dispersant-Inhibitor package or DI package." Typically, a DI package can contain a magnesium petroleum sulfonate, an ashless dispersant, and an oxidation inhibitor (e.g., zinc dialkyldithiophosphate). Lubrizol 27563 analyzes 2.40 weight percent zinc, 1.9% magnesium, 2.15% phosphorous, 0.17% nitrogen and 5.071 sulfur.

FURTHER DESCRIPTION The following Table I presents typical properties of stabilized hydrocracked oils which can be used in practice of the present invention.

TABLE I *All oils den-axed lo a 0F. pour point h chilling in a sohcnt. aml stabilizing b extraction with I'urfural.

In general, such hydrocracked and stabilized hydrocracked oils (of high VI and low pour point) can be substituted in whole or in part for the hydrorefined paraffinic oil or solvent refined paraffinic lube component in the compositions (or process where applicable) of U.S. pat. No. 3,502,567 of Ivor W. Mills and Glenn R. Dimeler, issued Mar. 24, I970, for example. In such compositions the oxidation inhibitor concentration can be reduced when 85-100% of the solvent refined lube is replaced by the stabilized hydrocracked oil.

For example, in a mist lubricant formulation which contains a solvent refined paraffinic lube, the partial or whole substitution of a hydrocracked (preferably, a stabilized hydrocracked) lube permits the use of a lower concentration of the polymeric additive for a given degree of stray fog. This provides improved reclassification performance (for a given degree of stray fog) in the composition containing the hydrocracked lube. Alternatively, a lower molecular weight polymer can be used in the composition containing the hydrocracked lube.

In hydraulic oils, whether soap or polymer thickened, a preferred oil contains mainly DBPC (e.g., 0.5 weight percent) as the antioxidant and a minor amount (e.g., 0.0l0. 1% Zn) of zinc dialkyl dithiophosphate to impart antiwear properties.

In turbine oils, the use of a stabilized hydrocracked oil in combination with an ashless or virtually ashless inhibitor improves the performance in test where sludging is measured (as in Mil-L-l7672B). In engine oils, the composition containing an antioxidant (preferably zinc dialkyl dithiophosphate at levels imparting 0. l-3% Zn in the final composition) and a stabilized hydrocracked oil provides better performance in the Sequence IIIc test. Also, when tested in a natural gas burning engine, the composition containing the stabilized hydrocracked oil is superior.

As an additional component (to hydrorefined oils and unhydrorefined oils) in textile oils or refrigeration oils, high viscosity index hydrocracked oils and/or hydrogenated polyolefin oils (e.g., polybutene in the C C range) can be used. The polyolefin or hydrocracked oil can be partially or fully hydrogenated.

ILLUSTRATIVE EXAMPLES The following automatic transmission fluid is prepared by blending each of the components with stirring at room temperature:

888 wt. of a blend of furfural stabilized hydrocracked paraffinic oil having a F. pour point. a viscosity of 140 SUS at 100F. and 105 ASTM VI;

0.5 wt. 7r of dilauryl thiodipropionate (antioxidant);

0.2 wt. of Naugatuck 438, manufactured by Uniroyal. an amine antioxidant;

0.3 wt. Lubrizol I097 (zinc dialkyl dithiophosphate) (an antioxidant and wear inhibitor);

0.5 wt. Amoco I21 (barium alkyldiphosphonate) (a detergent);

0.3 wt. 7: overbased magnesium petroleum sulfonate having a base number of 300;

0.1 wt. tricresylphosphate;

3.0 wt. 7: a refined petroleum oil containing 95% aromatics as a seal swell agent;

ppm. dimethyl silicone defoamer having a viscosity of 60,000 cs at 68F.;

3.0 wt. of synthetic sulfurized sperm (see Canadian Ser. No. l34,l56) and 4 3.75 wt. dispersant polymethacrylate viscosity index improver which is a copolymer of laurylmethacrylate and methylmethacrylate having grafted thereon n-vinyl-2-pyrrolidinone.

This automatic transmission fluid provides superior performance (compared to a similar formulation containing solvent refined lube of the same viscosity) in the General Motors T-l2 Powerglide Low Energy Transmission Cycling Test.

EXAMPLE II A limited slip differential fluid is prepared by blending the following components at room temperature:

70.0 vol. furfural stabilized hydrocracked oil having a viscosity of 500 SUS at F. VI of;

21.6 vol. unstabilized hydrocracked bright stock (2,500 SUS at 100F.);

0.5 vol. Friedel-Crafts condensation products of chlorinated paraffinic wax with phenol (pour depressant) 7.4 vol. an chlorinated pressure additive comprising a mixture of zinc phosphorodithioate and cholorinated hydrocarbons containing 3% Zn, 3% P, 16.5% C1 and 16% S;

0.5 vol. di-n-butyl tin dilaurate; and

I0 p.p.m. dimethyl silicone defoamer having a viscosity of 60,000 cs at 68F.

The high traction components of U.S. Pat. No. 3,608,385 of Irl N. Duling et al, issued Sept. 28, 1971, can be added to this fluid to increase the traction coefficient thereof.

EXAMPLE III A turbine oil is prepared by blending each of the following components (in parts by weight) with stirring:

99.4 furfural stabilized hydrocracked oil having an SUS viscosity of at 100F.;

0.2 Enjay Paraflow I49 (pour depressant); and

0.4 ditertiary butyl paracresol.

Enjay Paraflow 149 is a Friedel-Crafts reaction product of chlorinated biphenyl.

This oil passes all turbine requirements for low sludge except for M-L-l7642B. If 0.75 parts Vanderbuilt Vanalube 664 is used instead of the DBPC, the formulation can pass M-L-I762B.

This oil passes over 2000 hours of the D-943 test. A similar turbine oil containing a solvent refined paraffinic lube failed after 1500 hours of the D-943 test.

Vanalube 664 is a mixture of DBPC and amine type oxidation inhibitors and also includes a small amount of Butyl Zinate (zinc di-n-butyl carbamate).

EXAMPLE IV An expecially high quality l0W-40 engine oil is made by blending the following (in parts by weight) with stirring:

42.2 solvent refined paraffinic oil viscosity of H0 SUS at 100F., ASTM VI of 104; 42.2 solvent refined paraffinic oil of 210 SUS at l00F., ASTM VI of 103; 9.0 Acryloid 954, VI builder; and 6.6 Lubrizol 4446. Lubrizol 4446 is the more common commercial designation of the product previously referred to as Lubrizol 27563 and further identified by the IR scan of FIG. 3 herein. Properties of this oil are shown in Table II below.

TABLE 11 continued Vol. 7: of 100 SUS (at 100F.) ASTM Test naphthenic distillutc* 0 Characteristics Method Results Solvent refined lube oil 190 160 No. Viscosity. cP/0F. D2602 2100 5 Viscosity. SUS/100F. D2161 447 *Naphthenic acid-free (i.c.. tot-.11 acid number or "neutralization numhcr" less No. Viscosity. SUS/210F. D2161 83.5 than 0.2 mg. KOH/g).

Viscosity Index D2270 105 ASTM D2272. Viscosity. cSt/2 1 11F. D445 16.40 Gravity. AP1 D287 30.0 g S B3? 1 The test oils also contain 1.25% Vanlube 664, antlox- OUT. C010, 0,500 I45 1dant and rust 1nh1b1tor package. The data 1nd1cate that P the naphth enic distillate improves the oxidation inhibi- Egggfig B22: tor response of hydrocracked lubes, while reducing the sulfurf/t D129 0.44 ox1dat1on 1nh1b1tor response of the conventlonal sol- D189 vent refined lubes. However, the addition of hydrore- Foam. Tend/Stab D892 15 Sequence 1. ml 5/0 fined naphthemc 0115 to convent1onal solvent refined S q g g lubes does improve inhibitor response. Nu 52322: visual B/right As used herein, the term hydrocracked parafti ic Magnesium, '71 0.146 lube refers to a hydrocracked 011 havmg a v1scos1ty- No. Zinc 7r 0.185

Phosphorous 0'] 65 70 grav ty constant no greater than 0.8 19. Naphthenl c (1n Sulfatcd Ash. 7! D874 1.0 cludmg relat1vely naphthemc 0115) have a VGC 1n the range of 0.820 to 0.899, the more preferred naphthenic SAE 10W-40 Mast-met- Classification sacs 011s bemg 1n the range of 0840-0899. The hydrocracked paraffinic oils can be obtained by hydrocrack- When 1 10 and 210 $115 stabilized hydrocracked oils 35 mg g i ifi jg Smce hydmcrackmg are substituted for 90100% of the solvent refined oils, cause re 0 e the Zinc dialkyl dithiophosphate content of the oil can EXAMPLE 1 be reduced by %(e.g.,0.l8%Znto0.14%Zninfinal M t I t h d I k d lb oil) and the oil will perform at least as well in the Se- 0 8 n i f u quence lllc test. Furthermore, the Acryloid 954 can be f gconflendlona so i." g u es) reduced to 8.5% and the oil will still perform at least as i Prev] 6 gcredse E f er well as is indicated in Table I1. 0! fi s a" or exam? t; :h b i O dOIt dvltllg Preferably, with the stabilized hydrocracked oil, enexce. economy g I e gine oils can contain 0.070.18% Zn (as zinc dithiozg 19 g was e decor mg phosphate), depending on desired performance. to e O owmg 0mm The V1 builder of FIG. 2 can be substituted in whole or in part for the Acryloid 942. COmPmLm llume Hydrocracked l 10 SUS (at 100F.) lube 81.8 EXAMPLE v Zinc dialkyl dithiophosphatc in carr- (A 5959 r 9.07 z 0.6 The ox1dat1on stab111ty of hydrocracked paraffimc mufi i d -i i n) 1 1.5 lube oils is improved by the addition of small amounts 9 P g Lubrizql 2 contalmn I I 1' I'll. il'lll 7X1 I (up to 15%) of unhydrorefined naphthemc dlstillate. and j f t fz i Such 1mprovement is observed in the rotary bomb ox1- Mg. 2n. P and N 6.1 dation test (RBOT)**as follows VOL 7 of SUS (at 00cm Table 111 herein presents typical data of commercially naphthenic distillate* 0 1o 15 available naphthenic distillate oils which can be R301 300% minutes blended with hydrocracl qed lube to provide improved hydrocracked 111111: 011 205 264 257 ox1dat1on stab111ty (1nclud1ng 1mproved response to additives which are oxidation inhibitors).

TABLE III TYPICAL DATA COMMERClALLY AVAILABLE NAPHTHENIC DlSTlLLATE OlLS ASTM ASTM Property Designation Oil A Oil No. 3 Oil B Oil C Oil D Oil E Oil F Oil G ()il H Viscosity. SUS at 100F D-2l6l-66 108 156 208 310 515 780 1276 2525 5945 Viscosity. SUS at 210F D-2161-66 38.2 41 43.2 46.8 52.4 58.8 68 87.2 API Gravity at 60F 0- 287-67 22.2 22.1 21.0 20.] 19.6 19.1 18.4 17.6 17.3 Specific Gravity at 60F 0-1250-56 .9206 .9194 .9279 v .9334 .9365 .9396 .9440 9490 .9509 Flash Point. CDC. F D- 92-66 320 330 345 355 380 390 405 430 495 Volatility 22 hrs. at 225 Wt. '71 D- 972-56 7.58 5.96 5.40 4.35 3.08 2.11 1.67 0.16 0.02 Pour Point. F D- 97-66 45 35 30 l5 -l0 5 0 +10 +20 Color. ASTM D-l500 D-1500-64 1.25 1.75 1.75 2.0 2.0 2.5 3.0 3.5 5.75 Molecular Weight D-2502-67 295 325 325 345 355 370 380 395 450 Viscosity-Gravity Constant D-250l-67 0.884 0.878 0.884 0.887 0.885 0.885 0.885 0 889 0.884 Refractive Index ,3" D-1747-62 1.5081 1.5079 1.5121 1.5160 1.5167 1.5190 1.5210 1.5222 1.5250 Refractivity Intercept D-2159-64 1.0502 1.0479 1.0500 1.051 1 1.0503 1.0510 1.0508 1.0495 1.0495 Carbon Type Analysis D-2140-62 Aromatic Carbon Atoms. C,,/r 21 20 21 22 21 22 22 21 20 Naphthenic Carbon Atoms C 7: 37 36 37 36 37 36 36 39 31! Paraffinic Carbon Atoms C,,/1 42 44 42 42 42 42 46 40 42 Molecular Type Analysis (Clay TABLE Ill-continued TYPICAL DATA COMMERClALLY AVAILABLE NAPHTHENlC DlSTlLLATE ()lLS ASTM ASTM Property Designation ()il A Oil No. 3 Oil B O C ()il D Oil E ()il F Oil G Oil H Gel) 0-2007-56'1' Asphaltencs. wt. '71 O (J (l l) (J (l U U 0 Polar Compounds. Wtf/r 1.1 1.2 1.8 2.0 2.5 2.7 3.0 2.7 4.2 Aromatics. Wtf/r 43.0 41.7 44.0 44.0 43.8 43.6 44.0 44.8 44.7 Total Aromatics 44.1 42.9 45.8 46.0 46.3 46.3 47.0 47.5 48.9 saturates. Wt. "/1 55.9 57.1 54.2 54.0 53.7 53.7 53.0 52.5 51.1 Analinc Point. F D- (11 1-64 145 156 152 153 156 162 166 172 183 ASTM Type [12216-69 H13 H13 lil3 I03 )3 l(l3 lo l()3 l()3 ()ils. B. C. F. and F are blends of oils A and (i The invention claimed is:

l. A composition, useful as a lubricant, comprising an unhydrorefined naphthenic distillate of lubricating viscosity in amount sufficient to provide improved oxidation stability and a major amount of a hydrocracked lube oil which has been solvent extracted or hydrorefined to reduce or inhibit sludging of the oil on exposure to ultraviolet light and having a viscosity in the range of 803,()0() SUS at 100F., and a minor amount of an oxidation inhibitor consisting essentially of a mixture of phenolics, amines, and zinc carbamate, said amount being effective to permit said composition to pass the ASTM D-943 oxidation test for a period of at least 300 hours, said amount being less than would be required to permit the same D-943 test performance cracked lube oil has been solvent extracted.

* l l= l 

1. A COMPOSITION USEFUL AS A LUBRICANT, COMPRISING AN UNHYDROREFINED NAPHTHENIC DISTILLATE OF LUBRICATING VISCOSITY IN AMOUNT SUFFICIENT TO PROVEDE IMPROVED OXIDATION STABILITY AND A MAJOR AMOUNT OF A HYDROCRACKED LUBE OIL WHICH HAS BEEN SOLVENT EXTRACTED OR HYDROREFINED TO REDUCE OR INHIBITS SLUDGING OF THE OIL ON EXPOSURE TO ULTRAVIOLET LIGHT AND HAVING A VISCOSIT IN THE RANGE OF 80-3,000 SUS AT 100*F., AND A MINOR AMOUNT OF AN OXIDATION INHIBITOR CONSISTING ESSENTIALLY OF A MIXTURE OF PHENOLICS, AMINES, AND ZINC CARBAMATE, SAID AMOUNT BEING EFFECTIVE TO PERMIT SAID COMPOSITION AND TO PASS THE ASTM D-943 OXIDATION TEST FOR A PERIOD OF AT LEAST 300 HOURS, SAID AMOUNT BEING LESS THAN WOULD BE REQUIRED TO PERMIT THE SAME D-943 TEST PERFORMANCE FOR SAID COMPOSITION WHEREIN THE HYDROCRACKED LUBE OIL IS REPLACED BY AN UNHYDEOCRCKED SOLVENT REFINED LUBE OF THE SAME VISCOSITY, VISCOSITY-GRAVITY CONSTANT AND VISCOSITY INDEX.
 2. The composition of claim 1 wherein said naphthenic distillate is substantially free of naphthenic acids.
 3. The composition of claim 2 wherein the amount of said naphthenic distillate is in the range of 0.5-20 volume %.
 4. The composition of claim 1 wherein said hydrocracked lube oil has been solvent extracted.
 5. The composition of claim 3 wherein said hydrocracked lube oil has been solvent extracted. 